You're right that their home page at http://www.hercules.com/uk/webcam/bdd/p/63/hercules-dualpix-chat-and-show/#top does not specifically mention Win 7, but the first link is to a 'selection' page.
Fill in the details. I chose as a test Webcam > USB > Dualpx HD webcam > Drivers
And at the bottom of the page I saw a direct download option for "Windows 7/Vista SP2/XP SP3 - 55 MB. It is an executable file so caution is needed, eg; download and save, do not download and Run.
They could have done it all better.